Manufacture of nitroglycerin.



FREDERIC LEWIS NATHAN, JAMES MILN THOMSON, WILLIAM RINTOUL,

NITED STATES PATEN OFFIQE.

AND ANDREW SCOTT, OF WALTHAM ABBEY, ENGLAND,

I MANUFACTURE OF NITROGLYCERIN.

Specification of Letters Patent.

Patented Jan. 22, 1907.

Application filed June 6,1906. Serial No. 820,336;

To aZZ whom it may concern.-

Be'it known that we, FREDERIC LEWIS NATHAN, lieutenant-colonel R. A., JAMES MILN THOMSON, WILLIAM RINTOUL. and ANDREW Soo'rT, subjects of the King of Great Britain and Ireland, and all residing at the Royal Gunpowder Factory, Waltham Abbey, in the county of Essex, England, have invented certain new and useful Improvements in the Manufacture 0f Nitroglycerin, of which the following is a specification.

Our invention relates to the manufacture of nitrogl cerin.

Hereto ore it has been usual to manufacture nitroglycerin by the addition of glycerin to a mixture of nitric and sulfuric acids. The nitric acid used for this mixture is what is known as fuming" nitric acid, containing about 91.5 per cent. HNO and the sulfuric acid is the acid containing about ninety-six per cent. H 80 In manufacturing nitroglycerin according to previous methods it has heretofore only been possible to obtain a yield inany ordinary apparatus of about two hundred and ten to two hundred and fifteen parts of nitroglycerin for every one hundred parts of glycerin used.

The object of the present invention is to manufacture nitroglycerin in such a manner that, first, an increased yield of nitroglyc-' erin is obtained; second, a decreased quantity of mixed acids is required; third, a plant of reduced ca acity for a given weight of glycerin can file used; fourth, a decreased quantity of waste acid requiring denitration and concentration is obtained, involving less loss of nitroglycerin by solution in the Waste acids.

These improvements in manufacture resulting from our invention reduce the cost of the finished nitroglycerin.

The invention consists in nitrating glycerin in a mixture of N ordhausen acid and fuming nitric acid, the proportion of nitric acid to sulfuric acid in the mixture being greatly increased over the proportion in common use. The resulting Waste acids are approximately of the same composition as are those now generally produced.

In carrying our invention into eflect we gradually run ten parts of glycerin into a mixture of acids containing twenty-eight parts of nitric acid, of which about 91.5 per cent. is HNO and thirty-four parts of N ordhausen sulfuric acid containing about twenty per cent. 80,. The nitroglycerin formed is separated from the waste acid in any usual manner.

It is found that by using the acids above described the yield of nitroglycerin is increased to two hundered and thirty er cent. of the weight of the glycerin used; a so, by the use of the Nordhausen acid we are enabled to use less of the mixed acids containing a larger proportion of nitric acid, while the waste acids are of approximately the same composition as are those ducedj also, the proportion of waste acid to nitro lycerin being less less nitroglycerin is absor ed and lost.

In the example above described we have specified N ordhausen acid containin twenty per cent. S0 and this is the strengt of acid which we have found most suitable. N ordhausen acid containing other proportions of SO may, invention, the proportion used being to a certain extent dependent upon physical considerations, such as temperature and the like.

Having thus described and ascertained our invention, what we claim as new, and desire to secure by Letters Patent, is-

1. The process of manufacture of nitroglycerin which consists in treating glycerin with a mixture of Nordhausen sulfuric acid and nitric acid, substantially as described.

2. The process of manufacture of nitroglycerin which consists in adding ten parts of lycerin to a mixture containin twentyeig t parts of nitric acid of which a out 91.5

er cent. is HNO and thirty-four parts of ordhausen sulfuric acid containing about twenty per cent. of SO, substantially as described.

In testimony whereof we have signed our names to this specification in the presence of two subscribin witnesses.

FREERIC LEWIS NATHAN. JAJMES MILN THOMSON. WILLIAM RINTOUL. ANDREW SCOTT.

Witnesses I I G. F. WARREN, Bnnrnnra Hiderrnnws now generally prohowever, be used according to our 

